Spinner spreaders for particulate material are well known in the art, both for agricultural application, lawn care, and road maintenance application. Typically, such spreaders are mounted onto a truck body, truck chassis, trailer, or slid into a truck's dump body. The spreader includes a material storage bin(s), a conveyor system(s) and rotating spinner(s). The conveyor transfers material from the storage bin(s) to the spinner(s). The spinner(s) broadcast the material across the field, lawn, or road. Usually a single spinner or a pair of laterally spaced spinners are provided, with a material divider plate positioned above the spinner(s) to direct the material from the discharge end of the conveyor(s) onto the spinner(s). A wide range of spinner diameters are in use with a general understanding that the amount of material to be spread and the size of the broadcast area are proportional to the diameter of the spinners.
Recently, a new technology has emerged known as variable rate technology. Unlike the past when it was desirable to apply a constant rate of material per acre or lane mile, variable rate technology advances the benefits of varying rates while moving across the field, lawn, or roadway. As it relates to agriculture, it is now desirable to apply different rates of a material in different grids of the same field in order to obtain optimum pH and/or fertility values over the entire field. As for roadways, it is now common practice, for example, to apply a varying rate of de-icing materials during the winter depending on the grade of the road; increasing rates on steep roads or at intersections while decreasing rates on less traveled or level roads. This new variable rate technology has challenged makers of broadcast spreaders to provide a spreader that can achieve optimum spread patterns while applying varying low and high rates of materials while the spreader is traveling at variable ground speeds (MPH) over the field, lawn or road. Variable ground speeds combined with variable application rates result in a variable amount of material (cubic feet per minute) passing across the spinner(s). As the rate of material changes, it is necessary to change the drop point onto the spinner(s) to achieve optimal spread patterns.
Furthermore, it is common to spread different density materials with the same spreader, which makes it necessary to change the drop point onto the spinner(s) to achieve optimal spread patterns when switching from high to low density material applications.
In conventional prior art spreaders, the drop area of the material from the conveyor(s) is fixed in relationship to the spinner(s). Minor adjustability of the drop area has been accommodated by adjusting the position of a material divider(s) such that the material is deflected by the divider(s) onto a different drop area on the spinner(s). However, such movement of the divider(s) relative to the spinner(s) does not provide uniform material flow through the divider(s) creating difficulty in achieving uniform spread patterns. Furthermore, the aperture of the divider(s) must be large enough to accommodate the highest rate of application lest it would hinder material flow onto the spinner(s). The divider aperture therefore creates a null zone where the divider setting or the divider movement has no consistent affect on the drop area of the material during a change from high to low rate applications. Also, the movement of the divider(s) is substantially limited due to the structure of the divider and/or conveyor and does not allow for the proper material placement on the spinner for achieving optimum spread patterns of both low and high rates of material. Therefore, the limitations of a conventional prior art spreader does not allow achieving optimal spread patterns when applying variable volume rates of material or different densities of material.
Accordingly, a primary objective of the present invention is the provision of an improved particulate material spreader that achieves proper placement of both low and high volumetric and density based rates of material.
Another objective of the present invention is the provision of a particulate material spreader having spinner(s) which are incrementally adjustable, fore and aft, relative to the conveyor(s) discharge end and material divider(s).
A further objective of the present invention is the provision of an improved spreader for agricultural, lawn care, and road maintenance use with uniform material flow from the conveyor(s) discharge end through the material divider(s) and onto the adjustable spinner(s) of the spreader.
Another objective of the present invention is the provision of an improved particulate material spreader wherein the position of the spinner(s) is quickly and easily adjustable.
A further objective of the present invention is the provision of spinner(s) for particulate material spreader which can be manually adjusted to accommodate varying low and high application rates of material onto an area, such as a field, lawn or road.
Another objective of the present invention is the provision of an improved particulate material spreader to automatically adjust the spinner(s) position, fore and aft in relationship to the conveyor discharge end and material divider, based on the rate being applied while the spreader is moving over the field, lawn, or road at either fixed or variable ground speeds (MPH).
These and other objectives will become apparent from the following description of the invention.